Fuel oils



Patented Nov. 3, 1953 FUEL OILS Charles Henry Braithwaite, Jr., Wood River, and George Ambrose Martin and Reid Edward Sutton, East Alton, Ill., assignors to Shell Development Company, San Francisco, Calif., a corporation of Delaware No Drawing. Application October 20, 1950, Serial No. 191,332

11 Claims. 1

This invention relates to petroleum fuels and, more particularly, to novel fuel oil compositions having greatly improved pour-point characteristics.

One of the characteristics of fuel oils which is limited by standardized specifications is the property known as pour-point. Because of this requirement that fuel oils have a specified minimum pour point, rather severe limitations are inherently placed upon the relative quantities of gasolines, light distillate oils, residual fuels, etc., which may be produced from a given crude petroleum stock. For example, in order to meet the pour-point specification, a distillate furnace oil must contain a certain proportion of fairly light components, or cannot contain more than a certain proportion of heavy components. If, however, the pour point of the fuel is reduced in some manner, a smaller proportion of the volatile components is required in the furnace oil, and larger quantities of lighter distillates such as kerosene and gasoline can be produced. Likewise, during periods of peak demand for fuel oils, greater quantities of such oils can be produced by including therein larger amounts of heavier fractions. Other beneficial results of a suitable means of lowering the pour point of fuel oils will be obvious to those skilled in the art.

It has now been found that the pour point of a petroleum fuel oil may be lowered by the inclusion of small amounts of a compound containing the structural group,

if CN (1) where X is a chalkogen or an NH group. It will be noted that the above formula gives one a wide choice of satisfactory materials, the only limitation being that the compound should have a solubility in the oil greater than about 0.0005 per cent by weight, and preferably greater than about 0.001 per cent by weight. A particularly effective embodiment of the invention is obtained when the bond on the carbon atom in Formula 1 is I satisfied by an amino or substituted amino group and X is an oxygen or sulfur atom. These ureas,

ciently soluble in most fuel oils. The preferred organic radicals are hydrocarbon radicals, which may be aliphatic or cyclic, straight or branched chain, saturated, unsaturated or aromatic or any combination thereof. Thus, the hydrocarbon radicals may be, for example, alkyl, alkenyl, aryl, alkaryl, aralkyl, etc.

The ureas may be substituted with other than pure hydrocarbyl radicals. For example, the hydrocarbyl radical may be substituted with amino, hydroxy, alkoxy, aryloxy, carboxylate, oxo, halogen, or like substituents; or the nitrogen of the urea may be directly attached to a non-carbon atom, such as another nitrogen atom, to form semicarbazides, semicarbazones, and the like.

While the ureas are the preferred embodiment of the present invention, non-urea materials having the structure of Formula 1 may be used if desired. For example, amides or substituted amides, carbamates, amidines such as guanidine or stearamidine, etc, are all effective, provided the solubility requirement is met. Likewise, combinations of the above essential structure may be used, as in biuret, or derivatives thereof.

The foregoing describes in relatively general terms the structural requirements and physical properties of the additives of the present invention. For specific examples of satisfactory compounds, reference may be had to the tables presented below. The data therein were obtained by measuring the pour points (determined according to ASTM Specification 13-97-47 except that observations were made at temperature intervals of 2 F. rather than 5 F., and two or more determinations were made on each specimen and the average result reported) of a Numher 2 fuel 011 (ASTM Specification D-396-39T), f

with and without the various pour-point depressants of this invention.

The No. 2 fuel has the following properties:

Unless otherwise noted, the pour-point depressant was used at a concentration of 0.0015 per cent by weight.

depressing amount of a metal-free compound having the formula,

wherein R1 is a hydrocarbyl radical and R2 is selected from the group consisting of hydrogen atoms and hydrocarbyl radicals.

4. A distillate fuel oil having an initial pour point of at least about F. containing dissolved therein a minor but eiTective pour-point depressing amount of a metal-free compound having the formula,

wherein R1 is a hydrocarbyl radical and R2 is selected from the group consisting of hydrogen atoms and hydrocarbyl radicals.

5. A fuel oil having an initial pour point of at least about 10 F. containing dissolved therein a minor but effective pour-point depressing amount of a metal-free compound having the formula,

X N N wherein X is a chalkogen having an atomic number of from 8 to 16, said compound having at least one hydrocarbyl group attached to a nitrogen atom.

7. A distillate fuel oil having an initial pour point of at least 10 F. containing a minor but effective pour-point depressing amount of lauryl urea dissolved therein in amount greater than 0.0005% by weight and not greater than 1.0% by weight.

8. A distillate fuel oil having an initial pour point of at least 10 F. containing a minor but effective pour-point depressing amount of N- phenyl N n butyl N .phenylurea dissolved therein in an amount greater than 0.0005% by weight and not greater than 1.0% by weight.

9. A distillate fuel oil having an initial pour point of at least 10 F. containing a minor but efiective pour-point depressing amount of N- phenyl N n propyl-N-phenylurea dissolved therein in an amount greater than 0.0005% by weight and not greater than 1.0% by weight.

10. A distillate fuel oil having an initial pour point of at least 10 F. containing a minor but effective pour-point depressing amount of phenylthiourea dissolved therein in an amount greater than 0.0005% by weight and not greater than 1.0% by weight.

11. A distillate fuel oil having an initial pour point of at least 10 F. containing a minor but eifective pour-point depressing amount of stearylurea dissolved therein in an amount greater than 0.0005% by weight and not greater than 1.0% by weight.

CHARLES HENRY BRAITI-IWAITE, JR. GEORGE AMBROSE MARTIN. REID EDWARD SUTTON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,263,445 Reiff Nov. 18, 1941 2,343,393 Bergen Mar. '7, 1944 2,373,049 Pedersen Apr. 3, 1945 2,393,934 Reifif Jan. 29, 1946 2,396,156 Clarkson Mar. 5, 1946 FOREIGN PATENTS Number Country Date 312,774 Great Britain June 6, 1929 

1. A DISTILLATE FUEL OIL HAVING AN INITIAL POURPOINT OF AT LEAST ABOUT 10* F. CONTAINING DISSOLVED THEREIN A MINOR BUT EFFECTIVE POUR-POINT DEPRESSING AMOUNT OF A METAL-FREE COMPOUND HAVING THE FORMULA. 